Drug and Gene Therapy for Treating Variant Transthyretin Amyloidosis (ATTRv) Neuropathy.

Variant Transthyretin Amyloidosis (ATTRv) neuropathy is an adult-onset, autosomal dominant, lethal, multisystemic disease due to the deposition of mutated transthyretin (TTR) in various organs, commonly involving the peripheral nerves and the heart. Circulating TTR tetramers are unstable due to the presence of mutated TTR and dissociate into monomers, which misfold and form amyloid fibrils. Although there are more than 140 mutations in the TTR gene, the p.Val50Met mutation is by far the commonest. In the typical, early-onset cases, it presents with a small sensory fibre and autonomic, length-dependent, axonal neuropathy, while in late-onset cases, it presents with a lengthdependent sensorimotor axonal neuropathy involving all fibre sizes. Treatment is now available and includes TTR stabilizers, TTR amyloid removal as well as gene silencing, while gene editing therapies are on the way. Its timely diagnosis is of paramount importance for a better prognosis.

Long-term safety and efficacy of patisiran for hereditary transthyretin-mediated amyloidosis with polyneuropathy: 12-month results of an open-label extension study.

BACKGROUND: Hereditary transthyretin-mediated amyloidosis is a rare, inherited, progressive disease caused by mutations in the transthyretin (TTR) gene. We assessed the safety and efficacy of long-term treatment with patisiran, an RNA interference therapeutic that inhibits TTR production, in patients with hereditary transthyretin-mediated amyloidosis with polyneuropathy. METHODS: This multicentre, open-label extension (OLE) trial enrolled patients at 43 hospitals or clinical centres in 19 countries as of Sept 24, 2018. Patients were eligible if they had completed the phase 3 APOLLO or phase 2 OLE parent studies and tolerated the study drug. Eligible patients from APOLLO (patisiran and placebo groups) and the phase 2 OLE (patisiran group) studies enrolled in this global OLE trial and received patisiran 0·3 mg/kg by intravenous infusion every 3 weeks with plans to continue to do so for up to 5 years. Efficacy assessments included measures of polyneuropathy (modified Neuropathy Impairment Score +7 [mNIS+7]), quality of life, autonomic symptoms, nutritional status, disability, ambulation status, motor function, and cardiac stress, with analysis by study groups (APOLLO-placebo, APOLLO-patisiran, phase 2 OLE patisiran) based on allocation in the parent trial. The global OLE is ongoing with no new enrolment, and current findings are based on the interim analysis of the patients who had completed 12-month efficacy assessments as of the data cutoff. Safety analyses included all patients who received one or more dose of patisiran up to the data cutoff. This study is registered with ClinicalTrials.gov, NCT02510261. FINDINGS: Between July 13, 2015, and Aug 21, 2017, of 212 eligible patients, 211 were enrolled: 137 patients from the APOLLO-patisiran group, 49 from the APOLLO-placebo group, and 25 from the phase 2 OLE patisiran group. At the data cutoff on Sept 24, 2018, 126 (92%) of 137 patients from the APOLLO-patisiran group, 38 (78%) of 49 from the APOLLO-placebo group, and 25 (100%) of 25 from the phase 2 OLE patisiran group had completed 12-month assessments. At 12 months, improvements in mNIS+7 with patisiran were sustained from parent study baseline with treatment in the global OLE (APOLLO-patisiran mean change -4·0, 95 % CI -7·7 to -0·3; phase 2 OLE patisiran -4·7, -11·9 to 2·4). Mean mNIS+7 score improved from global OLE enrolment in the APOLLO-placebo group (mean change from global OLE enrolment -1·4, 95% CI -6·2 to 3·5). Overall, 204 (97%) of 211 patients reported adverse events, 82 (39%) reported serious adverse events, and there were 23 (11%) deaths. Serious adverse events were more frequent in the APOLLO-placebo group (28 [57%] of 49) than in the APOLLO-patisiran (48 [35%] of 137) or phase 2 OLE patisiran (six [24%] of 25) groups. The most common treatment-related adverse event was mild or moderate infusion-related reactions. The frequency of deaths in the global OLE was higher in the APOLLO-placebo group (13 [27%] of 49), who had a higher disease burden than the APOLLO-patisiran (ten [7%] of 137) and phase 2 OLE patisiran (0 of 25) groups. INTERPRETATION: In this interim 12-month analysis of the ongoing global OLE study, patisiran appeared to maintain efficacy with an acceptable safety profile in patients with hereditary transthyretin-mediated amyloidosis with polyneuropathy. Continued long-term follow-up will be important for the overall assessment of safety and efficacy with patisiran. FUNDING: Alnylam Pharmaceuticals.

The frequency of central nervous system complications in the Cypriot cohort of ATTRV30M neuropathy transplanted patients.

BACKGROUND: Hereditary transthyretin amyloidosis (ATTR) is a hereditary, sensorimotor and autonomic neuropathy caused by deposits of mutated transthyretin (TTR). The commonest TTR mutation is V30M (ATTRV30M) with patients usually living for about 10 years after disease onset. Liver transplantation (LT) until recently was considered the standard treatment. OBJECTIVE AND METHODS: This study aims to assess the frequency of CNS complications in post-LT patients from the Cypriot cohort. Epidemiological data were collected for all genetically confirmed ATTRV30M neuropathy patients diagnosed at CING since 1992, and CNS-associated symptoms were assessed and evaluated by two neurology specialists. RESULTS: Out of the 48 transplanted patients, 10 (20.8%) presented with a CNS complication. All patients had ocular involvement, mainly glaucoma (7/10). Eight presented with transient focal neurological episodes (TFNEs), with expressive dysphasia being reported by four of them. The mean time of TFNE-emergence was 16.6 years after the LT. Three died from cerebral hemorrhage. CONCLUSIONS: CNS complications in post-LT ATTRV30M patients are not rare and usually manifest themselves at a time that surpasses the mean time the patients would have survived without a LT. CNS involvement is associated with increased mortality, due to cerebral hemorrhage.

A novel case of inclusion body myositis and myasthenia gravis.

The co-existence of myasthenia gravis and other inflammatory myopathies has been reported in the literature before, but no clinical cases involving inclusion body myositis have been reported. We report a case of a 67-year-old patient who presented with dysphagia, exhibiting the typical electrophysiological features of postsynaptic neuromuscular junction defect with positive muscle acetylcholine receptor antibodies, consistent with the diagnosis of myasthenia gravis. Nevertheless, response to acetylcholinesterase inhibitors and immunomodulatory treatment was unexpectedly poor. As the disease progressed, the patient developed asymmetric muscle weakness, initially affecting mainly the quadriceps and the finger flexors. Muscle MRI imaging supported the presence of an inflammatory myopathy and muscle biopsy confirmed the diagnosis of inclusion body myositis. Thus, our patient represents the first reported overlap case of myasthenia gravis and inclusion body myositis.

Prevalence of Anti-JC Virus (JCV) Antibodies in the Multiple Sclerosis (MS) Population in Cyprus: A Retrospective Study.

BACKGROUND AND PURPOSE: Progressive multifocal leukoencephalopathy (PML) is a debilitating disease of the central nervous system caused by the ubiquitous polyomavirus JC (JCV) in immunocompromised hosts. In recent years, a new subpopulation of patients at risk for PML has emerged, due to the growing use of immunomodulatory or immunosuppressive therapies in autoimmune diseases such as multiple sclerosis (MS). The anti-JCV antibody index is used as a stratification tool in assessing the risk of developing PML. The objective of this study was to retrospectively describe the prevalence of anti-JCV antibodies in the MS population in Cyprus. METHODS: We retrospectively collected the demographics of 214 MS patients in Cyprus who were screened for anti-JCV antibodies using the STRATIFY JCV™ assay between September 2011 and June 2018. Logistic regression analysis was used to examine the effect of demographic variables on seropositivity, and bivariate tests were used to assess the association between demographic characteristics and JCV AI index. RESULTS: A total of 214 MS patients in Cyprus were tested. Overall anti-JCV antibody prevalence was 45.8% (95% confidence interval 37.2%-55.8%). We could not establish a significant association between seropositivity and increasing age or sex. In the subgroup analysis of natalizumab-treated patients, the annual seroconversion rate was 4.5%. CONCLUSIONS: Overall seroprevalence of anti-JCV antibodies in MS patients in Cyprus using the STRATIFY JCV assay was lower than the worldwide reported mean. Although previously reported, in our study, the anti-JCV antibody seropositivity was not associated with increasing age or sex.

Transthyretin deposition in the eye in the era of effective therapy for hereditary ATTRV30M amyloidosis.

BACKGROUND: Ocular abnormalities have been known to occur in hereditary amyloidotic polyneuropathy since the 1950s. While vitreous opacities and scalloped pupils were described early it has become evident that every component of the eye from the conjunctiva to the retinal vasculature can be involved. Reports from the major centres in Japan, Portugal and Sweden, which primarily treat patients with ATTRV30M, have indicated that with the increased longevity seen in patients treated with liver transplantation the frequency of the more severe eye findings, notably vitreous opacities and subsequent glaucoma, are being detected more frequently. METHODS: In an attempt to confirm that the experience was similar in a broader range of locales we performed a survey of ten treatment centres in eight countries to determine the frequency of severe ocular abnormalities (vitreous opacities and glaucoma) in 804 patients with V30M disease and whether there was any relationship to treatment with liver transplantation or the transthyretin stabilizer tafamidis. RESULTS: The data indicate that the frequency of these abnormalities increases with increasing duration of disease. In patients broadly matched for duration of disease the frequency was higher in subjects who had undergone liver transplantation than in those who were untreated. CONCLUSIONS: Retrospective surveys are subject to a number of potential biases. In this case, the major potential confounders were defining the time of disease onset and physician bias in choice of therapy, particularly regarding the choice of patients and the time in their course when they should undergo liver transplantation, and when and whether they should receive tafamidis. Nonetheless it appears that the incidence of severe ocular abnormalities in V30M subjects from centres around the world is similar to those found in centres in the areas endemic for this variant protein. The incidence increased with duration of disease regardless of therapy with the highest frequencies seen in patients more than ten years after diagnosis who had undergone liver transplantation.

Patisiran, an RNAi therapeutic for the treatment of hereditary transthyretin-mediated amyloidosis.

Hereditary transthyretin-mediated amyloidosis is a rapidly progressive, heterogeneous disease caused by the accumulation of misfolded transthyretin protein as amyloid fibrils at multiple sites, and is characterized by peripheral sensorimotor neuropathy, autonomic neuropathy and/or cardiomyopathy. Current treatment options have limited efficacy and often do not prevent disease progression. Patisiran is a novel RNA interference therapeutic that specifically reduces production of both wild-type and mutant transthyretin protein. In Phase II, III and long-term extension studies in patients with hereditary transthyretin-mediated amyloidosis, patisiran has consistently slowed or improved progression of neuropathy. In addition, the Phase III trial demonstrated significant improvements in quality of life measures and indicators of cardiomyopathy. Here, we highlight efficacy and safety data from the patisiran clinical trial programme.

Epidemiology of ATTRV30M neuropathy in Cyprus and the modifier effect of complement C1q on the age of disease onset.

BACKGROUND: ATTRV30M amyloidosis is a lethal autosomal dominant sensorimotor and autonomic neuropathy caused by amyloid deposition composed of aggregated misfolded TTR monomers with the V30M mutation. The age of onset in patients with ATTRV30M varies in different foci and the mechanism behind it is still unknown. METHODS: The tertiary neurology center following all ATTRV30M patients in Cyprus was used to collect demographic data to estimate; prevalence, incidence, penetrance, anticipation, time from disease onset to diagnosis and transplantation. Ocular, cardiac and leptomeningeal involvement in transplanted patients was explored. Correlation of C1q tagging SNPs with age of disease onset was carried out. RESULTS: Prevalence and incidence for ATTRV30M neuropathy in Cyprus are 5.4/100,000 and 0.3/100,000 respectively. Mean age of onset is 40.6 years and anticipation is 8.3 years. Penetrance reaches 51% and 75% by the ages of 50 and 80 years respectively. In liver transplanted patients rates of ocular, cardiac and leptomeningeal involvement were estimated to be 60%, 20% and 16%, respectively. C1q polymorphisms correlated with age of disease onset. CONCLUSIONS: ATTRV30M neuropathy has a rising prevalence in Cyprus due to improved survival of patients. Late onset complications are becoming a major problem. Complement C1q appears to be a modifier in this disease.

Pharmacological Stimulation of Phagocytosis Enhances Amyloid Plaque Clearance; Evidence from a Transgenic Mouse Model of ATTR Neuropathy.

Hereditary ATTR V30M amyloidosis is a lethal autosomal dominant sensorimotor and autonomic neuropathy caused by deposition of aberrant transthyretin (TTR). Immunohistochemical examination of sural nerve biopsies in patients with amyloidotic neuropathy show co-aggregation of TTR with several proteins; including apolipoprotein E, serum amyloid P and components of the complement cascade. Complement activation and macrophages are increasingly recognized to play a crucial role in amyloidogenesis at the tissue bed level. In the current study we test the effect of two C5a receptor agonists and a C5a receptor antagonist (PMX53) on disease phenotype in ATTR V30M mice. Our results indicate that amyloid deposition was significantly reduced following treatment with the C5a receptor agonists, while treatment with the antagonist resulted in a significant increase of amyloid load. Administration of the C5a receptor agonists triggered increased recruitment of phagocytic cells resulting in clearance of amyloid deposits.

C1q ablation exacerbates amyloid deposition: A study in a transgenic mouse model of ATTRV30M amyloid neuropathy.

ATTRV30M amyloid neuropathy is a lethal autosomal dominant sensorimotor and autonomic neuropathy, caused by deposition of amyloid fibrils composed of aberrant transthyretin (TTR). Ages of onset and penetrance exhibit great variability and genetic factors have been implicated. Complement activation co-localizes with amyloid deposits in amyloidotic neuropathy and is possibly involved in the kinetics of amyloidogenesis. A candidate gene approach has recently identified C1q polymorphisms to correlate with disease onset in a Cypriot cohort of patients with ATTRV30M amyloid neuropathy. In the current study we use a double transgenic mouse model of ATTRV30M amyloid neuropathy in which C1q is ablated to elucidate further a possible modifier role for C1q. Amyloid deposition is found to be increased by 60% in the absence of C1q. Significant up regulation is also recorded in apoptotic and cellular stress markers reflecting extracellular toxicity of pre-fibrillar and fibrillar TTR. Our data further indicate that in the absence of C1q there is marked reduction of macrophages in association with amyloid deposits and thus less effective phagocytosis of TTR.

An unusual case of suprascapular nerve neuropathy: a case report.

INTRODUCTION: Suprascapular nerve neuropathy constitutes an unusual cause of shoulder weakness, with the most common etiology being nerve compression from a ganglion cyst at the suprascapular or spinoglenoid notch. We present a puzzling case of a man with suprascapular nerve neuropathy that may have been associated with an appendectomy. The case was attributed to nerve injury as the most likely cause that may have occurred during improper post-operative patient mobilization. CASE PRESENTATION: A 23-year-old Caucasian man presented to an orthopedic surgeon with a history of left shoulder weakness of several weeks' duration. The patient complained of pain and inability to lift minimal weight, such as a glass of water, following an appendectomy. His orthopedic clinical examination revealed obvious atrophy of the supraspinatus and infraspinatus muscles and 2 of 5 muscle strength scores on flexion resistance and external rotation resistance. Magnetic resonance imaging showed diffuse high signal intensity within the supraspinatus and infraspinatus muscles and early signs of minimal fatty infiltration consistent with denervation changes. No compression of the suprascapular nerve in the suprascapular or spinoglenoid notch was noted. Electromyographic studies showed active denervation effects in the supraspinatus muscle and more prominent in the left infraspinatus muscle. The findings were compatible with damage to the suprascapular nerve, especially the part supplying the infraspinatus muscle. On the basis of the patient's history, clinical examination, and imaging studies, the diagnosis was suspected to be associated with a possible traction injury of the suprascapular nerve that could have occurred during the patient's transfer from the operating table following an appendectomy. CONCLUSION: Our case report may provide important insight into patient transfer techniques used by hospital personnel, may elucidate the clinical significance of careful movement of patients following general anesthesia, and may have important implications for patient safety techniques, including those outlined in the World Health Organization Surgical Safety Checklist program.

Complement C1Q polymorphisms modulate onset in familial amyloidotic polyneuropathy TTR Val30Met.

BACKGROUND: Familial amyloidotic polyneuropathy (FAP) TTR Val30Met is a lethal autosomal dominant sensorimotor and autonomic neuropathy due to a substitution of methionine for valine at position 30 of the transthyretin (TTR) gene. Amyloid, composed of mutated TTR, is deposited in the peripheral nervous system, myocardium and kidneys. Considerable variability in the age of onset and penetrance of the disease occurs in different countries. Penetrance in Sweden, Cyprus and Portugal is 2%, 28% and 80% respectively. Environmental and genetic factors are believed to contribute to this variability. So far, no single modifier gene has been unequivocally associated with age of onset or penetrance. METHODS: Candidate modifier genes were chosen from among those coding for chaperone proteins co-localized with TTR deposits in peripheral nerves. Seventy one TTRVal30Met carriers, 51 affected and 20 asymptomatic, belonging to 22 unrelated Greek-Cypriot families, and 59 normal controls were recruited for this study. Sequencing of the coding regions of TTR, serum amyloid P (APCS) and complement C1Q (A, B and C) genes was performed and APOE genotypes were determined. We searched for correlations between various polymorphisms of chaperone proteins and age of disease onset. RESULTS: Four new and 4 previously described single nucleotide substitutions were identified. One polymorphic site in C1QA (rs172378) and one in C1QC (rs9434) as well as the epsilon2 allele correlated with age of onset (p<0.05). CONCLUSIONS: Our study has identified polymorphisms which may influence the FAP-TTR Val30Met phenotype. Identifying modifier genes and their protein products may contribute to therapeutic advances.

Epidemiological, clinical and genetic study of familial amyloidotic polyneuropathy in Cyprus.

UNLABELLED: OBJECTIVES. To define the incidence and prevalence of familial amyloidotic polyneuropathy (FAP) TTRVal30Met on the island of Cyprus. To study the clinical phenotype and genetic features of FAP TTRVal30Met in the Cypriot population. METHODS: The clinical and neurogenetic databases were used to identify probands with FAP TTRVal30Met and detailed family trees were constructed. Potential carriers of the mutation were identified from the family trees and assessed clinically and genetically. Transthyretin was completely sequenced in patients and potential carriers. RESULTS: Thirty-six patients carrying the TTRVal30Met mutation (one homozygote) from 22 families were identified. On 1 December 2003 the prevalence of FAP was 3.72/100,000 while the incidence is estimated to be 0.69/100,000 per year. The phenotype observed was characteristic for a length dependent sensorimotor and autonomic neuropathy with neuropathic pain. Mean age of onset was 46 years. Penetrance is estimated to be 28% and positive anticipation in the age of onset is found. CONCLUSION: FAP is relatively prevalent in Cyprus which may be considered as another endemic focus of the disease in Europe. The mean age of onset and penetrance is different from the Portuguese and Swedish populations. Understanding the biological factors that determine these differences could potentially lead to therapeutic advances.

Malignant mutation in the lamin A/C gene causing progressive conduction system disease and early sudden death in a family with mild form of limb-girdle muscular dystrophy.

BACKGROUND: Lamin proteins A and C are major functional and structural components of the nuclear lamina. Mutations of the LMNA gene have been associated with dilated cardiomyopathy, conduction system defects and skeletal muscle dystrophy simultaneously, in variable involvement. We report on a family with a mutation of the lamin A/C gene (c.908-909delCT). METHODS: Thirty five members of the family of a proband were studied and underwent clinical and genetic evaluation. Family members were considered to be affected if they demonstrated conduction system defects, limb-girdle muscular dystrophy, dilated cardiomyopathy, carried the lamin A/C mutation or suffered sudden death. RESULTS: Fifteen members of the family were considered to be affected. Conduction system defects were the major feature of the affected members (67%), with variable involvement of dilated cardiomyopathy (33%), and limb-girdle muscular dystrophy (53%). Sudden death occurred in four members (27%) and was the presenting feature in three (20%) of the affected members at an early age. Mutation c.908-909delCT was confirmed in 12 of the affected members. The pattern of inheritance was autosomal dominant. CONCLUSION: Lamin c.908-909delCT mutation is malignant compared to other dilated cardiomyopathy-associated mutations of the Lamin A/C gene. Patients with this mutation have rapid progression of atrioventricular conduction abnormalities, and sudden death may be the presenting feature. Early identification of affected families and consideration of an implantable defibrillator is important in this setting.

Naturally occurring utrophin correlates with disease severity in Duchenne muscular dystrophy.

Although there is good experimental data that utrophin, the autosomal analog of dystrophin, can ameliorate the phenotype in dystrophinopathies, there is scant evidence from human data to support this hypothesis. We investigated in diagnostic muscle biopsies from 16 patients with Duchenne muscular dystrophy (DMD) the level of utrophin expression using quantitative immunoblot analysis. In 13 of 16 patients, in whom there was adequate follow-up data, utrophin expression was correlated to two clinical endpoints: age at reaching Hammersmith score of 30/40 and age at becoming wheelchair-bound. We found that utrophin expression increases with age in DMD and that there is a significant positive correlation between the quantity of utrophin at initial biopsy and time to becoming wheelchair-bound.

Phenotypic spectrum of disorders associated with glycyl-tRNA synthetase mutations.

We describe clinical, electrophysiological, histopathological and molecular features of a unique disease caused by mutations in the glycyl-tRNA synthetase (GARS) gene. Sixty patients from five multigenerational families have been evaluated. The disease is characterized by adolescent onset of weakness, and atrophy of thenar and first dorsal interosseus muscles progressing to involve foot and peroneal muscles in most but not all cases. Mild to moderate sensory deficits develop in a minority of patients. Neurophysiologically confirmed chronic denervation in distal muscles with reduced compound motor action potentials were features consistent with both motor neuronal and axonal pathology. Sural nerve biopsy showed mild to moderate selective loss of small- and medium-sized myelinated and small unmyelinated axons, although sensory nerve action potentials were not significantly decreased. Based on the presence or absence of sensory changes, the disease phenotype was initially defined as distal spinal muscular atrophy type V (dSMA-V) in three families, Charcot-Marie-Tooth disease type 2D (CMT2D) in a single family, and as either dSMA-V or CMT2D in patients of another large family. Linkage to chromosome 7p15 and the presence of disease-associated heterozygous GARS mutations have been identified in patients from each of the five studied families. We conclude that patients with GARS mutations present a clinical continuum of predominantly motor distal neuronopathy/axonopathy with mild to moderate sensory involvement that varies between the families and between members of the same family. Awareness of these overlapping clinical phenotypes associated with mutations in GARS will facilitate identification of this disorder in additional families and direct future research toward better understanding of its pathogenesis.

Reversible inflammatory and vacuolar myopathy with vitamin E deficiency in celiac disease.

We report a patient with late-onset celiac disease and neurological manifestations including myopathy, polyneuropathy, and ataxia. Laboratory investigations showed anti-gliadin antibodies and severe vitamin E deficiency. Muscle biopsy revealed inflammatory infiltrates and rimmed vacuoles, similar to those found in inclusion-body myositis. A gluten-free diet and vitamin E supplementation reversed both the clinical neurological manifestations and the abnormalities in the muscle biopsy. Anti-gliadin antibodies were no longer present. This case illustrates the spectrum of neurological complications of celiac disease and documents the occurrence of reversible pathology resembling inclusion-body myopathy in the muscle.